That the best of us are not blameless and that all of us need God's mercy is something that Helen Richards Campbell expressed well in this short poem:­-

When some fellow yields to temptation, and breaks a conventional law,
We don't look for the good in his make-up, but Lori how we look for the flaw.
No one asks who did the tempting, nor allows for the battles he's fought.
His name becomes food for the jackals - the saints who have never been caught!
I'm a sinner, O Lord, and I know it, I am weak and I blunder and fail,
I am tossed on life’s stormy means, like a ship that is caught in a gale.
I am willing to trust in your mercy, to keep the commandments you taught, But deliver me, Lord, from the judgment of the saints who have never been caught!

..... which is complemented by the following (especially applicable to road-users!):-

"When the other fellow takes a long time to do something, he's slow-but when I take the same time, I’m just being thorough. When he states his opinion strongly, he's bull-headed-but I'm just being firm. When he overlooks some of the rules, he's being foolhardy. I'm just being confident. When he makes a mistake, he deserves all he gets. When I make a mistake, it's sheer bad lack. When he can't make up his mind about an issue, he's a ditherer-but I’m just being impartial." Sounds familiar?